The IPv6 (Internet Protocol Version 6, Internet Protocol Version 6) is considered as a core of the next generation Internet, which attracts attentions and gets promotion of governments and telecommunication operators of all countries.
In a process of IPv6 evolution, evolution solutions, such as dual-stack+NAT (network address translation), 6RD (IPv6 rapid deployment), and DS-LITE (dual-stack lite) mainly exist, where the DS-LITE solution is mainly directed to middle and later periods of the IPv6 evolution, that is, an IPv4 isolated island crosses over an IPv6 network to access the IPv4 Internet. For an IPv4 uplink packet, in the DS-LITE solution, a tunnel (IPv4 over IPv6) to an AFTR (Address Family Transition Router) is generally initiated on a CPE (customer premise equipment), and the tunnel is terminated in the AFTR, and IPv4 to IPv4 NAT, an uplink packet is forwarded to an IPv4 network.
A current network generally conforms to a networking manner. For example, a terminal or customer premise equipment accesses a BNG (broadband network gateway) by adopting a PPPOE (point to point protocol over Ethernet, point to point protocol over Ethernet), and the BNG performs authentication and charging on an AAA server (authentication, authorization, and accounting server) by adopting a Radius (Remote Authentication Dial In User Service, remote authentication dial in user service) protocol. In this networking manner, generally, only one or a few DS-LITE tunnels are established between one BNG and the AFTR.
In an implementation process of the present invention, the inventor finds that the prior art has at least the following problem. In the IPv6 evolution in the prior art, when multiple links between a gateway and an address family transition router AFTR are corresponding to the same tunnel for network address translation, after receiving a packet sent by the gateway, the AFTR needs to distinguish customer premise equipment according to an IP address of the customer premise equipment; if IP addresses of the customer premise equipment are overlapping or are the same, the address family transition router cannot distinguish different terminal users, so that a terminal user that sends a packet cannot receive feedback.